/Engine/Source/Editor/UnrealEd/Classes/Editor/UnrealEdEngine.h
Duplicates the given actors. Handles the case where you are trying to duplicate PrefabInstance actors.
virtual void DuplicateActors ( const [TArray](API\Runtime\Core\Containers\TArray)< [AActor](API\Runtime\Engine\GameFramework\AActor) * > & InActorsToDuplicate, [TArray](API\Runtime\Core\Containers\TArray)< [AActor](API\Runtime\Engine\GameFramework\AActor) * > & OutNewActors, [ULevel](API\Runtime\Engine\Engine\ULevel) * InLevel, const FVector & LocationOffset )